1. Field of Invention
This invention relates to the neutralization of hazardous formaldehyde solutions to reduce the risk of direct and airborne contact by the use of chemically treated dried materials.
2. Background of the Invention
Formaldehyde solutions have been used as a tissue fixative and transport solution for biological study for over a century. Only in the last several decades have we learned the potential hazards of formaldehyde to the technicians exposed to this material.
Commonly used in the health care industry to preserve biological samples for pathological analysis, formaldehyde solutions remain the common fixative of choice. In a routine health care environment, histologists receive multiple biological tissue samples in these formaldehyde solutions from a variety of sources throughout an average workday. Once received into the pathology laboratory, the biological samples that are contained in the formaldehyde solution are transferred to an open grossing board for analysis by a pathologist. Once studied on the grossing board, part or all of each sample is inserted into a tissue cassette. At this point, the biological sample is then inserted into a tissue processor, a machine that further subjects the sample to more formaldehyde solutions that are handled by the laboratory technician. In all of these procedures described above, the risk of both vapor and direct contact exposure for formaldehyde remains high for the laboratory technician.
While some measures have been taken to reduce the amount of formaldehyde vapor the pathologist and technician are notably exposed to such as fume hoods and monitors for exposure levels, attempts at absorbing and neutralizing formaldehyde solutions at the point of contact have been problematic. Current products on the market that attempt this goal either hold the formaldehyde solution in an absorbent material or chemically treat a fiber material with a wet chemical mixture, leaving the fiber material in a constant damp state. Holding the formaldehyde solution in an absorbent material has the problem of simply wicking the formaldehyde while continuing to broadcast the formaldehyde vapor into the technician's breathing area. Treating a fiber material with a wet chemical mixture has the additional problem of not absorbing other liquids or formaldehyde vapors present in the air.
These disadvantages, along with the increasing awareness of reducing formaldehyde vapor and contact exposure to the laboratory technician, increases the need for an improved method or technology for reducing this risk.
Formaldehyde polymerization by use of urea is a proven method of neutralizing formaldehyde. The reaction of formaldehyde with urea and acid will neutralize the formaldehyde. However, in practical use this reaction is slow, typically taking hours to completely neutralize the formaldehyde solution, including it's vapor-generating capabilities. Furthermore, the use of such a limited combination of materials would not be viable for an application such as responding to a formaldehyde spill or controlling formaldehyde vapor.
Accordingly, there is a need for a device and method to quickly neutralize formaldehyde not only for waste disposal, but to provide the practical applications of controlling a formaldehyde spill and restricting formaldehyde vapor. Current formaldehyde spill and vapor control methods suffer from a number of disadvantages:                a. Formaldehyde neutralization methods are not rapid or do not pass the American Society for Testing and Materials (ASTM) method test for presence of formaldehyde.        b. Many formaldehyde spill response and control products simply absorb or wick the formaldehyde, not providing neutralization, resulting in broadcasting the formaldehyde vapor back into the air.        c. Some formaldehyde spill response and control products are treated with wet chemicals and do not rapidly absorb formaldehyde vapor from the air.        